Method of laser soldering

Abstract

An additive that absorbs light at a given wavelength is added to a solder flux composition for use in laser soldering wherein the laser emits light of said given wavelength. The additive reduces the power required to melt the solder-flux combination and thereby improves soldering efficiency.

We claim: 
     
       1. In a method of soldering employing a flux composition and a Nd:YAG laser beam as the heat source, the improvement which comprises: adding an effective amount of a dye having the formula ##STR2## to said flux composition to increase the amount of light at the emission wavelength of said laser beam which is absorbed by said flux composition.   
     
     
       2. A method of soldering according to claim 1 wherein said dye is dissolved in a solvent compatible with said flux composition. 
     
     
       3. A method of soldering according to claim 2 wherein said flux composition further comprises glycolic acid. 
     
     
       4. A method of soldering according to claim 3 wherein said flux composition further comprises a wetting agent. 
     
     
       5. A method of soldering according to claim 4 wherein said dye is present in an amount from about 0.02 to about 1% by weight of the active flux composition. 
     
     
       6. A flux composition for use with a Nd:YAG laser soldering system, comprising: a flux; and   a dye having the formula ##STR3## in an effective amount to increase the amount of light at the emission wavelength of a Nd:YAG laser which is absorbed by said flux composition.   
     
     
       7. A flux composition according to claim 6 wherein said dye is dissolved in a solvent compatible with said flux composition. 
     
     
       8. A flux composition according to claim 7 wherein said flux composition further comprises glycolic acid. 
     
     
       9. A flux composition according to claim 8 wherein said flux composition further comprises a wetting agent. 
     
     
       10. A flux composition according to claim 9 wherein said dye is present in amounts from about 0.02 to about 1% by weight of the active flux composition.